The Rosetta Stone unlocked Egyptian hieroglyphs by repeating one decree in three scripts

When French soldiers unearthed a broken granodiorite slab near Rosetta in 1799, they had found a translation key 2,000 years in the making. Its inscription is a priestly decree from 196 BC honoring the boy-king Ptolemy V — and the same text appears three times, in Egyptian hieroglyphs, the cursive Demotic script, and Ancient Greek.

Scholars could still read Greek, so the stone effectively came with its own translation. The breakthrough lay in the cartouches — the oval rings that enclosed royal names. Reasoning that these foreign Greek names had to be spelled out phonetically, Jean-François Champollion matched the signs inside them to the names Ptolemy and Cleopatra, sharing letters between the two and prying loose the sound value of individual hieroglyphs.

He was not working alone. The Englishman Thomas Young had already made real headway, cracking much of the Demotic and identifying several phonetic signs, and the two men became rivals for the credit. But it was Champollion’s 1822 announcement that hieroglyphs were a phonetic script, not mere pictures, that finally broke the code.

The stone itself orders that the decree be carved “in hieroglyphics, the demotic script, and Greek” in temples across Egypt.

The object’s own journey was just as tangled. The British seized it from the French after Napoleon’s defeat — hence the English inscription painted along its side — and it became the British Museum’s most-visited object, even as Egypt presses for its return.